Bull float



P 1961 s. D. LAPHAM 2,999,261

BULL FLOAT Filed Oct. 10, 1955 INVENTOR. S/DNEV D. LAPHAM ATTORNEYSUnited States Patent 2,999,261 BULL FLOAT Sidney D. Lapllam, RED. 2, Box316, Martinez, Calif.

Filed Oct. 10, 1955, Ser. No. 539,310 3 Claims. (Cl. 15-2353) Thisinvention relates to and in general has for its object the provision ofa bull float wherein the angle between the bull float handle and thebull float shoe varies automatically in response to the change in thedirection of movement of the shoe.

Basically, a bull float consists of a shoe rigidly fixed to a push-pulloperating handle, and which is moved back and forth across wet concretefor the purpose of leveling said concrete prior to smoothing orfinishing the leveled concrete. In such a leveling operation, the shoesshould be maintained level or slightly inclined in the direction of thetravel of the shoe so that the concrete can be properly worked. The only.way of controlling the angularity of a fixed-handle bull float is toraise or lower the handle, and. when long handles are required becauseof the concrete area being processed, this becomes awkward anddiflicult.

More specifically, the object of this invention is the provision of abull float wherein the bull float shoe is attached to its handle throughan inverted trapezoidal linkage to constrain the angle between the shoeand the handle automatically to decrease in response to a pull on thehandle and to increase in response to a push on the handle when the shoeis in traction with a body of concrete.

A further object of this invention is the provision in a bull float ofthe character above described of means, operable in response to therotation of the bull float handle, for varying and limiting the extentto which the angle between the shoe and its handle changes in responseto the push and pull on the handle.

Still another object of this invention is the provision in a bull floatof the character above described of means for locking the bull floatshoe to its handle at any desired angle in response to the rotation ofsaid handle.

The invention possesses other advantageous features, some of which, withthe foregoing, will be set forth at length in the following descriptionwhere those forms of the invention which have been selected forillustration in the drawings accompanying and forming a part of thepresent specification, are outlined in full. In said drawings, one formof the invention is shown, but it is to be understood that it is notlimited to such form, since the invention as set forth in the claims maybe embodied in other forms.

Referring to the drawings,

FIG. 1 is a top plan view of a bull float embodying the objects of myinvention.

FIG. 2 is a vertical midsection taken on the section line 2-2 of FIG. 1.

FIG. 3 is a fragmentary transverse vertical section taken on the sectionline 3-3 of FIG. 2.

The hull float shown in these various figures comprises a rectangularwooden shoe I faced with a sheet of rubber 2 and fastened to arectangular metal angle frame 3 by bolts 4.

Secured to the frame 3 on either side of its transverse center line areupstanding flanges 5 and 6, and welded to and hedging the side membersof the frame 3 is a central strap 7. Welded to the upper face of thestrap 7 is an upstanding web 8 formed with a notch or valley 9 definedby downwardly converging, inclined edges or walls 11 and 12.

Journaled in and extending between the flanges 5 and 6 are front andrear offset rods or links 13 and 14 pro- 2,999,261 Patented Sept. 12,1961' vided with central horizontal and parallel portions 15 and 16.Pivoted on the horizontal link portions 15 and 16, and bridging suchportions, are a pair of upstand ing, parallel plates 17 and 18, andinterconnecting these plates and forming a rigid structure therewith,are a front pair of upper and lower parallel bars or straps 19 and 21and a rear pair of parallel bars or straps 22 and 23.

Welded to and between the bars 19 and 21 is a sleeve 24, and welded toand over the front end of the sleeve 24 is a plate 25. Rigidly attachedto the plate 25 coaxially with the sleeve 24 is an inwardly extendingthreaded stud 26 of a diameter substantially smaller than the diameterof the sleeve 24.

Welded to and between the rear bars 22 and 23 isa sleeve 27 coaxial withthe sleeve 24 of the same internal diameter.

Extending through the sleeves 27 and 24, with fairly close clearance, isthe forward section 28 of a tubular full float operating handle 29, thefront end thereof being threaded over the stud 26 and being arranged tohave substantial forward and rear travel thereon.

Eccentrically secured to the handle section 28 between the sleeves 24and 27 by pins 31 and 32 is a cam disc 33 accommodated within the notchor valley 9 of the web 8.

Secured to the free end of the handle section 28 by a coupling sleeve 34is an outer handle section 35, the two handle sections being of suchlengths as to produce together an operating handle of from 18 to 20 feetlong.

As a result of this construction, and by particular reference to FIG. 2,it will be seen that the shoe and its operating handle have beeninterconnected by what may be referred to as an inverted trapezoidallinkage in contrast to a parallelogrammatic linkage. If, as shown inFIG. 2, the cam disc 33 is in its lowermost position, and in substantialcontact with the bottom of the V- shaped notch or valley 9, the linkagewill be locked against movement, thereby to produce a rigid structure ofthe shoe and its handle. If, on the other hand, the operating handle isrotated axially through so that the narrowest portion of the cam disc isfacing downwardly as shown in dash line in FIG. 3, the handle can bebodily translated forward and backward relative to the shoe. Here itshould be noted that the dimensions of the cam disc, its eccentricity,and the height or depth of the notch or valley 9 should be such that inall positions of the cam disc, its rim will always be disposed withinthe confines of the notch. Furthermore, it should be noted that when inthe unlocked position of the earn, the operating handle is movedrearwardly relative to the shoe, both of the links 13 and 14 will rotateclockwise about their pivotal points with the flanges 5 and 6. However,the front link 13 will be rising, whereas the rear link 14 will bedescending, and as a result, the angle between the shoe and the handlewill decrease until the lower rim of the cam engages the left wall ofthe notch 9. 0n the forward movement of the handle relative to the shoethe reverse action will take place.

By rotating the cam disc 33 to some position intermediate its high andlow positions, the amplitude of movement of the handle relative to theshoe is correspondingly restricted, and consequently, the degree ofvariation of the angle between the shoe and the handle.

If the cam disc is centered with respect to the notch 9, the amplitudeof the angle through which the shoe is permitted to move in a clockwisedirection will be equal to its movement in a counterclockwise direction.However, by screwing the handle forward or backward the amplitude ofmovement of the shoe in one direction relative to the opposite directioncan be changed at will.

The frictional resistance or adhesion between the shoe and the concretebeing worked is, of course, suflicient to 2,ane,ee1

hold the shoe momentarily stationary upon a change in the direction ofmovement of the operating handle.

"It will, therefore, be seen that 'I have provided a hu1l float whereinits shoe and handle can be rigidly locked by a mere rotation of thehandle of not more than 180?, wherein the angle between the shoe andhandlewill automatically vary in response to a change inthe axialdirection of movement of the handle relative to the shoe, and whereinamplitude of change of such angle can be controlled in response to theaxial rotation of the handle.

For the purpose of the claims appendd hereto, the parallel plates 1.7and 1-8 and the bars or straps 19 and 21, and 22 and 23 can beconsideredas frame or rocker to which the bull float shoeis linked andto which the bull float handle is threadedly engaged.

I claim:

I. A bull float comprising: a shoe and rocker interconnected by a pairof spaced upwardly diverging links; a handle threadedly connected tosaid rocker transversely of said shoe; an upwardly extending web fixedto said shoe in the vertical plane of said handle, said Web being formedwith a V-shaped cam follower track; and a circular cam follower mountedon said handle eccentrically thereof and for rotation within theconfines of said notch.

2. A bull float comprising: a shoe; a handle mount disposed over saidshoe and rockahly connected thereto by a pair of upwardly diverginglinks; a handle rotatably mounted in said handle mount transversely ofsaid shoe; a web extending upwardly from said shoe in the vertical planeof said handle, said web being formed with a V- shaped cam track; and acamt'rack follower mounted on said handle for rotation therewith withinthe confines of said cam track.

3. A bull float comprising: a shoe; a handle mount disposed over saidshoe; ahandle rotatably mounted in saidvhandle mount transversely ofsaid shoe for rotation on its own axis; upwardly diverging linksinterconnecting said shoe and said handle mount for rockable motion; aV-shaped cam track extending upwardly from said shoe in the verticalplane of said handle; and a cam track follower eccentrically mounted onsaid handle within the (confines of said cam track and arranged whenrotated to its lowermost position to snugly seat in the lower end ofsaidcam track.

References Cited in the file of this patent UNITED STATES PATENTS AbramMay 21, 1929

